自定义jsp标签

1.类:

package ===============================;

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.tagext.BodyTagSupport;

public class DCAclTag extends BodyTagSupport {

    private static final long serialVersionUID = 1L;

    /**
     * 传入进来的值，权限判断需要的条见
     */
    private int control;
    private int permission;

    public int getControl() {
        return control;
    }

    public void setControl(int control) {
        this.control = control;
    }

    public int getPermission() {
        return permission;
    }

    public void setPermission(int permission) {
        this.permission = permission;
    }

    /**
     * doStartTag方法，如果value为true，那么 就计算tagbody的值，否则不计算body的值。
     */
    public int doStartTag() throws JspTagException {
        if (PermissionUtil.checkPermission(permission, control)) {
            return EVAL_BODY_INCLUDE;
        } else {
            return SKIP_BODY;
        }
    }

    /**
     * 覆盖doEndTag方法
     */
    public int doEndTag() throws JspTagException {
        try {
            if (bodyContent != null) {
                bodyContent.writeOut(bodyContent.getEnclosingWriter());
            }
        } catch (java.io.IOException e) {
            throw new JspTagException("IO Error: " + e.getMessage());
        }
        return EVAL_PAGE;
    }

}

在WEB-INF下的配置文件dc.tdl

<?xml version="1.0" encoding="ISO-8859-1" ?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee web-jsptaglibrary_2_0.xsd"
    version="2.0">
    <description>A tag library exercising SimpleTag handlers.</description>
    <tlib-version>1.0</tlib-version>
 
      <short-name>dctag</short-name>
      <uri>http://www.dc.com/tags</uri>
      <description>
        dctag
      </description>
 
    <tag>
       <name>acl</name>
       <tag-class>com.dc.platform.ss.permission.DCAclTag</tag-class>
       <body-content>jsp</body-content>
       <attribute>
             <name>control</name>
             <required>true</required>
             <rtexprvalue>true</rtexprvalue>
       </attribute>
       <attribute>
             <name>permission</name>
             <required>true</required>
             <rtexprvalue>true</rtexprvalue>
       </attribute>
   </tag>
</taglib>

web.xml下的配置:

    <taglib>
        <taglib-uri>http://www.dc.com/tags</taglib-uri>
        <taglib-location>/WEB-INF/dc.tld</taglib-location>
    </taglib>

页面调用: 引入改自定义标签

<%@ taglib prefix="dc" uri="http://www.dc.com/tags" %>

<dc:acl permission="<%=11%>" control="<%=aclState %>">    
    <li><a class="edit" href="s?md=${module.sn}&ac=turnNotice&rowId={rowid}" target="dialog" width="500" height="220" title="确定要转入公告吗？"><span>转入公告</span></a></li>
    <li class="line">line</li>
</dc:acl>